Method and apparatus for layer-by-layer filling and compacting cohesive building materials in layers in boreholes

Abstract

A method is used for the layer-by-layer filling and compaction of cohesive building materials, in particular of cohesive earth building materials, in at least one borehole near the surface. The cohesive building material is introduced into the at least one borehole and is compacted layer-by-layer using a conveying device comprising a stuffing piston driven by means of a push chain drive.

The invention claimed is: 
     
       1. A method for layer-by-layer filling and compaction of cohesive building materials, in particular of cohesive soil building materials, in at least one borehole near a surface, the method comprising:
 introducing the cohesive building material into the at least one borehole; and 
 compacting the cohesive building material layer-by-layer using a conveying device including a push chain drive and a stuffing piston driven by means of the push chain drive. 
 
     
     
       2. The method according to  claim 1 , wherein:
 the at least one borehole is lined with a protective tube; and 
 the cohesive building material is filled into the protective tube in portions. 
 
     
     
       3. The method according to  claim 2 , wherein the protective tube is withdrawn from the borehole step by step during the filling of the borehole with the cohesive building material in dependence on the quantity of cohesive building material introduced. 
     
     
       4. The method according to  claim 2 , wherein the stuffing piston of the conveying device, after filling a first portion of the cohesive building material into the borehole:
 pushes the cohesive building material through the protective tube to a bottom of the borehole; and 
 compacts the cohesive building material by a back-and-forth movement of the stuffing piston. 
 
     
     
       5. The method according to  claim 1 , wherein the stuffing piston of the conveying device, after filling a first portion of the cohesive building material into the borehole:
 pushes the cohesive building material in the borehole to a bottom of the borehole; and 
 compacts the cohesive building material by a back-and-forth movement of the stuffing piston. 
 
     
     
       6. The method according to  claim 1 , wherein after compacting a first portion of the cohesive building material in the at least one borehole:
 the stuffing piston is moved out of the borehole, 
 a further portion of the cohesive building material is filled into the borehole, 
 the stuffing piston is reintroduced into the borehole; and 
 the further portion of the cohesive building material is compacted by movement of the stuffing piston. 
 
     
     
       7. The method according to  claim 1 , wherein the cohesive building material for filling and compacting boreholes comprises:
 at least one absorbent in the form of a hydrogel; and 
 compactable soil building material. 
 
     
     
       8. The method according to  claim 7 , wherein the compactable soil building material is selected from swellable clay minerals, excavated soil or excavated drilling material. 
     
     
       9. The method according to  claim 7 , wherein the compactable soil building material comprises swellable clay minerals, the method further comprising producing the cohesive building material, including:
 producing the hydrogel from a crosslinked polyacrylate and water; and 
 adding a granulate of the swellable clay minerals to the hydrogel with mixing, whereby the granulate is wetted with the hydrogel. 
 
     
     
       10. The method according to  claim 9 , wherein the cohesive building material is producible from a mixture that contains:
 approximately 60 wt. % of the swellable clay mineral; 
 approximately 0.2 wt. % of the hydrogel; and 
 approximately 39.8 wt. % of water. 
 
     
     
       11. The method according to  claim 9 , wherein the cohesive building material has a solid, crumbly consistency and a moisture content of 15% to 50% water content. 
     
     
       12. The method according to  claim 7 , wherein the hydrogel is an acrylic-based hydrogel. 
     
     
       13. The method according to  claim 7 , wherein the compactable soil building material is a swellable clay mineral selected from the group consisting of bentonite, montmorillonite, kaolinites, smectites, illites, chlorites and mixtures thereof.